Removable control assembly for an electrical connector



April 3, 1962 M. LAzAR ET AL 3,028,575

REMOVARLE CONTROL ASSEMBLY FOR AN ELECTRICAL CONNECTOR Filed May 14, 1958 2 Sheets-Sheet 1 1N VENTOR.

MICHAEL LAz-AR". BY JOSEPH u. BERTRAM.

ATTORNEY April 3, 1962 M. LAzAR ET AL 3,028,575

RENOVABLE CONTROL ASSEMBLY FOR AN ELECTRICAL CONNECTOR [lllllllllll' INVENTORS MICHAEL LAZAR.

BY JOSEPH d. BERTRAM. MM

ATTORNEY United States Patent O 3,028,575 REMOVABLE CQNTROL ASSEMBLY FOR AN ELECTRICAL CDNNECTOR Michael Lazar, White Plains, N.Y., and Joseph J. Bertram, Norwalk, Conn., assignors to Burndy Corporation, a corporation of New York Filed May 14, 1958, Ser. No. 735,229 7 Claims. (Cl. 339-217) This invention relates to electrical connectors of the mating plug and receptacle type having pin and socket contacts and, more particularly, to electrical connectors having multiple pin and socket contacts which are removable from mating plugs and receptacles.

The advantages of electrical connectors of the mating plug and receptacle type having multiple pin and socket contacts is obvious, but the prior art connectors have not been completely satisfactory `because the known structures have often required a-large number of different components to be manufactured by relatively expensive methods. The contacts, once assembled in their respective plugs and receptacles, could not be removed nor could they be interchanged, and usually, the contacts required that a solder operation be performed in a dicult location under poor conditions.

One of the objects of this invention, therefore, is to provide a novel contact structure for use in electrical connectors of the mating plug and receptacle type.

Another object of this invention is to provide a contact assembly structure which allows easy insertion and ready removal from the supporting plug or receptacle.

Still another object of this invention is to provide a novel socket contact assembly which has a closed entry substantially preventing damage thereto due to the insertion of an oversized pin contact or probe.

A further object of this invention is to provide a novel socket contact having a single spring member functioning to retain the mating piu in the socket, ensure electrical Contact of the cooperating contact members and retain the socket in the supporting receptacle.

Still a further object of this invention is to provide an electrical connector structure having a minimum numberl of parts which can be readily and .inexpensively fabricated.

One of the features of this invention is the provision of a multiple contact plug and receptacle type electrical connector wherein the mating portions may be of identical design, each havingl a plurality of bores therethrough into which are removably disposed mating vpins and sockets. In one embodiment the pins and sockets each have a tubular body portion about which is disposed a retaining spring which locks the Contact to the receptacle. Each retaining spring includes a releasing cam surface which, when acted upon, permits the removal of the contact from the bore of the receptacle.

These and other features and objects of this invention will become more apparent by reference tothe following description taken in conjunction with the accompanying drawings, in which:

FiG. l is an exploded view partly in cross section of the receptacle and plug portions of an electrical connector, each containing a socket and pincontact respectively;

FiG. 2 is an enlarged View in perspective of the retaining spring for use with the contacts of the electrical connector of our invention; l

FlG. 3 is a front end view of the retaining spring shown in FIG. 2;

FlG. 4 is a plan view of the sheet metal stamping from which the retaining spring of FIG. 2 is formed;

FIG. 5 is a view in perspective of a pin contact made closed entry socket which is a socket limiting the size ICC from sheet ymetal for use in the electrical connector of our invention;

FIG. 6 is a view in perspective of the pin contact of FIG. 5 rotated 180 about its longitudinal axis;

FIG. 7 is a view in perspective of the socket contact formed from sheet metal for use in the electrical connector of our invention;

FIG. 8 is a side view in cross section of a plug and receptacle portion of an electrical connector having multiple pin and socket contacts;

FIG. 9 is a view in cross section of the mated pin and socket contacts of our invention;

l0 is a view in cross section showing the first step in the releasing of the contact of our invention from its housing; and

FIG. 11 shows the second step in the releasing of a contact of our invention from its housing.

Referring to FIG. 1 of the drawing, an exploded view of an electrical connector in accordance with .the principles of our invention is therein seen to comprise a socket il) with an associated socket retainer spring 12 which, as one of its functions, retains the socket 10 within the insulation housing 14. A pin or male contact 16 utilizes a pin spring retainer i3 in a similar manner to retain the pin'contact 16 within the bore of insulation housing 26. Insulation housing I4 having a socket 10 therein maybe termed a receptacle while the assembly of a pin contact l5 within insulationhousing 20 is normally called a pin contact 16. The central opening is substantially comi-- pletely enclosed by the entry portion 28 and forms a of the pin which can be acceptedtherein close to the substantially complete surrounding of the 'central openv-` The closed entry portion 28 of the socket 10 limit/sl the:

maxim-um size of mating pin contact which can lbe' accepted. lt is also desirable to' Vkeep the widthgof the longitudinal slot 32 of the T-slot 30 less than the diameter of the pin contact to be inserted. If the width of the slot 32 is Vgreater than the diameter of the pin inserted, it may be possible to cause the pin to project through` the slot and cause damage. lt is also desirable that any test probe which is inserted into the socket 10 have a diam eter greater than the width of slot 32.

A tubular-shaped retaining spring 12 shown in greater detail in FIGS. 2 and 3 may be formed of sheet metal shown in FIG. 4. 'Ihe blank shown in FIG. 4 is stamped from resilient spring material such as beryllium copper and the edges 36a and 36h are brought together to form a cylindrical shape having a longitudinal slit 36. One portion of retaining spring 12 forms a tongue 38 which is formed or pressed inwardly. The end of the tongue i8` is preferably slightly curved upward. The outer or for- Ward end of spring 12 is formed into La spiral lstrap '40 terminated on one end with a tab 42. The spiral strap 40 has its forward end 46 closer to the central axis of `the cylindrical spring 12 than the rearward edge 44 of the strap 40. Due to the slope or differential in the distance from the axis of the spring 12 to the edges 44 and 46, the spiral strap 4i) assumes a conical shape which functions as a camming surface. The rear end of the retaining spring 12 is upset in a plurality of places to form retaining louvers 48. In manufacturing the cylindrical spring for use with our invention, a tie or connecting strip 49 is utilized to join the spring blanks during manufacture and upon assembly easily detaches from the connecting strip by breaking along the dotted line 47.

The housing 14 for the contact assembly comprising contact and spring 12 includes an insulating block having a bore 50 therethrough. The bore 50 has a restricted portion 51 of minimium diameter under which the spring 12 is disposed when the spring and contact are inserted into the bore 50. The louvers 4S of the spring 12 cooperate with the shoulder 54 of the restricted portion 51 to limit the forward movement of the Contact assembly. The rear edge 44 of the spiral strap of the spring 12 engages the front shoulder 52 of the bore 50 so that the contact assembly cannot be pulled out or moved to the rear of the bore. The camming surface of the spiral strap permits the forward movement of the contact assembly within the bore until the louvers 48 engage the shoulder 54 at which time the rear edge 44 of the spiral strap, due to the tendency of the strap to return to its original shape, locks into the forward shoulder 52. The remaining portions 56 and 58 of the bore 50 receive the barrel and insulation ferrule portions of the contact, respectively. A shoulder 57 provides the transition between the two portions 56 and 5S of the bore 50. If desired, shoulder 54 may be chamfered to ease insertion of the contact.

The pin or male contact 16 comprises a body portion 60 having at the rear end thereof an insulation grip 62. In front of the insulation grip 62 is a peephole 63. The portion of the body between the insulation grip 62 and shoulder 64 comprises a wire receiver barrel into which the bared conductor is positioned. When the bared conductor is properly positioned in this barrel, a portion of it is visible through the peephole 63. Forward of the peephole63 is a shoulder 64. The front end of the body portion 60 includes a T-slot 66 comprising a longitudinal slot 68 and a transverse slot 70. It is seen that physically the pin contact so far described is similar to the socket Contact. However, the major difference is that the pin socket 16 has connected to the front end thereof a male or pin portion 72 which is adapted to be inserted within the socket contact 10. As shown, connected to the pin contact 16 in FIG. 1, an insulated conductor comprising insulation 74 over conductive wire 76 is joined to the contact 16 by having a portion of the insulation bared and the wire inserted into the barrel or Wire receiver of the body portion with the edge of the insulation 74 underlying the insulation grip 62 and a bared portion of the conductor underlying the peephole. A crimp or indentation 65 is then made in the body portion, coining the body to the bared wire 76 in the barrel and the insulation grip 62 is crimped to the insulation 74 as shown. Obviously, an insulated conductor can be connected to the socket contact 10 in a similar manner.

The pin contact 16 has associated with it a pin retainer spring 1S and an insulation housing 20. The spring 18 and the housing for the pin contact 16 are identical in structure and function to the spring retainer 12 and the housing 14 associated with socket contact 10 and are actually interchangeable therewith. In order to so indicate this identity, the reference characters of spring 12 and housing 14 have been applied to the drawing of spring 18 and housing 20 with the addition of the reference letter "a thereto.

While the socket contact 10 and pin contact 16 illustrated in FIG. 1 may be machined, it is advantageous to stamp or form or otherwise manufacture these components from sheet metal stock. Such sheet metal contacts are illustrated in FIGS. 5-7. Referring to FIGS. 5-7, the sheet metal pin and socket contacts 75 and 77, respectively, are each seen to comprise a generally tubular body 78 and 78a having longitudinal seams 80 and 80a therein. The pin contact 7S of FIGS. 5 and'6 has at the forward end thereof a pin portion S2 designed to tit within the ,esagera closed entry portion 100 of the socket body 78a. '111e pin 82 is separated from the body portion 78 by a transition S4 and the pin contact 75 is terminated at its rear end in a U-shaped trough 86 which has two upstanding ears 88 for gripping the wire and separated therefrom are larger ears 90 for gripping the insulation of a conductor. The contact iliustrated lin FIGS. 5 and 6 or 7 may be applied to a conductor in any well known manner by having the ears 88, 88a and 90, 90a about a bared conductor and its insulation, respectively. A cable stop 92 is provided at the rear of the T-shaped slot 94. The cable stop 92, 92a, is formed by pressing in a portion of the body wall. The T-shaped slot 94, 94a comprises a transverse slot 96, 96a and a longitudinal slot 98, 98a. The socket contact illustrated in FIG. 7 is similar in every respect to the pin contact shown in FIGS. 5 and 6 except that its forward end terminates in an entry 100 which is adapted to receive the pin contact 82.

ln order to produce a sheet metal closed entry contact of improved strength, it may be desirable to braze the seam 80a. This will ensure that the entry 100 will not accept an oversized probe or pin.

The completed Contact assembly for either the sheet metal or machined pin and socket comprises the contact plus the spring retainer. 'Ihe tubular spring retainer of FIG. 2 is fitted over the body portion of the Contact and has its inwardly depressed or deformed tongue 38 disposed into the longitudinal slot of the contact. The spiral strap 40 of the spring retainer is designed to fit within the transverse slot of the contact. Thus longitudinal movement of the spring on the contact is prevented because the depressed tongue 38 is in contact with the end of the longitudinal slot while the front edge 46 of the spiral strap 44 is in contact with the edge of the T-slot. Additional longitudinal movement is prevented by a portion of the strap 44 abutting the rear edge of the transverse slot. Rotary movement of the spring on the tubular socket body is prevented because the tongue 38 is depressed within the longitudinal slot and thus prevents relative axial rotation.

As an additional factor of safety, the retaining spring may be secured to the contact by spot welding or brazing or adhesive, although this is not essential since the cooperation of the T-slot and the spring will limit relative motion. The spring is formed in such a manner that the tubular body portion grips the body of the contact while the strap portion 44 has a tendency to maintain its original shape which provides a diameter at edge 44 which is larger than the diameter measured at the tubular body portion of the spring.

Referring to FIG. 8 of the drawing, there is therein shown a multiple contact connector in accordance with the principles of my invention. An insulation housing 102 having a plurality of bores therein 104 and 106 is provided. Each bore 104 and 106 is similar to the bores shown in FIG. 1. A socket contact 108 is inserted in the rear of 102 and moved forward into the bore 104. The rear cam edge of the tubular spring 110 locks onto the front shoulder of the bore 104, while the rear louvers prevent forward movement of the socket and spring assembly by engaging the middle shoulder of the bore 104. A wire 112 is inserted in the socket contact and the insulation grip 114 and wire receptacle 116 function as heretofore explained.

The bore 106 has a pin contact inserted therein. For purposes of illustration, a pin contact 109 is inserted in bore 106. A mating connector comprising an insulation housing 103 (which is identical to the housing 102) has bores 118 and 130 located therein. A pin contact 120 is inserted in bore 118 and in the usual manner heretofore explained, the spring 122 is utilized to position the contact within the bore and the conductor 124 is bared and inserted into the wire grip 128 while the insulation grip 126 is closed upon the conductor insulation. In a similar manner, a socket contact 107 is located within bore accesar;

d 130. It is obvious that since the pin and socket contacts are interchangeable within the bores of the insulation housing, it is necessary to make sure that mating contacts oppose one another in each housing 102 and 103.

To assure proper connection, polarizing connections 132, 133, 134, and 135 are utilized. Each of the polarizing connections 132-135 terminate in their rear with threaded portion 138 having lock washer 139 and nut 141) for mounting the plug onto a panel 142. In use, the two mating portions are brought together properly due to the polarizing connections and the pin contact fit into the socket contacts. Obviously, either housing may contain contacts of one type, i.e., all pins or all sockets, or, if desired, the pins and sockets may be located in the most convenient bores, provided mating contacts are located in opposed bores.

Referring to FIG. 9 of the drawing, a pair of mating contacts in accordance with the principles or" my invention are shown connected to each other. A plug 144 having an insulation housing containing a bore 148 is shown in the left-hand portion of, FIG. 9. Located within the bore 111% is a pin Contact 151i on which is disposed a pin retaining spring 152. The spring cam surface 154 engages the front shoulder 153 of the bore. The rear louvers 156 of the spring retainer 152. engage the rear l shoulders 169 of the restricted portion of the bore. The wire 166 is bared and inserted within the wire grips 162 which are crimped for mechanical strength and electrical connection and the insulation of the wire is gripped by means of insulation grip 164. The bore 148 is widened at the rear end thereof to provide sufficient clearance for the insulation grip. The receptacle 146 comprises the insulation housing containing a bore 19u in which is located a socket contact 168. The socket contact has mounted thereon a spring 173 having spring tongue 172 deformed inwardly. The cam surface 174 engages the front shoulder 176 of the bore to provide a locking action while the rear louvers 17S engage the rear shoulder 13) of the bore. The wire 186 is bared and the socket is crimped thereto at 182 while the insulation is gripped by a second crimp 184. The pin portion of pin contact 151i is inserted into the closed entry of the socket 168 and electrical contact is made thereby. Electrical contact is assured due to the tongue finger 172 pressing on the pin portion of the male contact Referring to FIG. 10, there is therein shown a removable socket contact 196 disposed in the bore 19t) of insulation housing 189 and retained therein by means of a spring retainer 1%. The rear louvers 201 abut upon the rear shoulders of the bore and prevent the socket assembly from being inserted too far. When the rear lonvers 201 abut the rear shoulder, the rear portion of the cam surface 192 locks onto the front shoulder ot the bore. To remove the contact, a tool 200 having a hollow bore 202 is fitted over the front portion 191 of the socket contact 196. As the tool 209 is fitted over the front portion of the socket contact, the spiral strap camming surface 192 is depressed, releasing it from the front shoulder as shown in FIG. 11. An axial force applied to the right now causes the withdrawal of the socket 196 from the bore 190 in insulation housing 189, permitting the removal of the contact.

Obviously, while a socket contact is shown in FIGS. 10 and 1l, the 'bore 202 of tool 200 is sufficiently deep to accept the pin portion of la pin contact 'and the operation of removability or insertion is substantially the same.

We have thus described our invention, but we desire it understood that it is not confined to the particular forms or uses shown and described, the same being merely illustrative, and that the invention may be carried out in other ways without departing from the spirit of our invention, and, therefore, we claim lbroadly the right to employ all equivalent instrumentalities coming within the scope of the appended claims, and by means of which, objects of our invention are attained and new results aco complished, as it is obvious that the particular embodiments herein shown and described are only some of the many that can be employed to attain these objects and accomplish these results.

We claim:

l. A spring for mounting on a tubular contact support comprising a resilient sheet metal =blank pressed into tubular form and including first means for cooperating with said support and preventing rotation of said spring thereon, second means for cooperating with said support for preventing longitudinal movement of said spring thereon and first and second opposed radially projecting longitudinally spaced stops for locking said spring within a housing said first radially projecting means comprising a strap portion for disposition concentrically on said tubular contact and having the rear edge thereof radially projecting so that said strap is of generally spiral shape a portion of said strap disposed Within the periphery of said tube.

2. An electrical contact yassembly for an electrical connector; said connector including a dielectric housing having a Contact receiving bore therein, said bore being restricted in `a ,portion thereof to provide front and back stop shoulders; said contact assembly comprising: a metallic Contact including integral conductor receiving and body portions; a sleeve disposed circumferentially about said contact and including outwardly extending retaining fianges adapted to engage the bore b-ack stop shoulder, a strap integral with said sleeve, its rear portion extending radially from said sleeve and adapted to engage said `bore front stop shoulder, land its front portion forming a camming surface; such that said rear portion is adapted to be disengaged from said bore front stop shoulder in response to a longitudinal thrust on said camming surface; said `Contact and circumferential sleeve being adapted to be jointly and concurrently inserted and removed from said housing bore; and means to xedly prevent rotational movement of said contact relative to said sleeve.

3. A retention clip for mounting on a contact, comprising: a sheet metal blank lfor-med into a tube and including first means for cooperating with said contact and preventing rotation of said clip thereon, second means for cooperating with said contact `for preventing longitudinal lmovement of said clip thereon, and first and second opposed, radially projecting, longitudinally spaced stops for locking said clip within a housing, said rst radially projecting means comprising a strap portion for disposition concentrically on said contact and having the rear edge thereof radially projecting, =a portion of said strap disposed within the periphery of said tube.

4. An electrical connector assembly comprising an insulation housing having a contact receiving fborc therein, said bore being restricted in a portion thereof to provide front and `back stop shoulders, an elongated cylindrical lmetallic contact body including at least a conductor receiving portion and a body portion, said body portion including a' transverse recess, a split tubular spring sleeve disposed circumferentially `about said contact and including outwardly extending retaining flanges to engage said back stop shoulder, a spirally wound strap integral with said spring having its rear portion thereof radially extending `from said tubular spring to engage said front stop shoulder and limit longitudinal movement of said contact and forming a camming surface such that said strap rear portion is disengaged in response to a longitudinal thrust on said camming surface, said strap cooperating with said recess on the body portion vfor limiting movement of said spring on said contact and said recess providing space into which said radially extending rear portion of said strap is disposed in response to said longitudinal thrust.

5. A resilient sheet metal blank for Iforming a tubular spring comprising a generally rectangular main body scction including a plurality of projecting detents adjacent the rear thereof formed by part shearing said sheet metal,

scadere a resilient tongue portion extending lforwardly from said main body section and an additional portion extending forwardly from said main `body section including a curved strap at the forward edge of said blank having one end terminating in a tab extending beyond the side of said main body section.

6. An electrical connector assembly comprising: an insulation housing having a front and a rear face and a contact receiving bore therethrough from face to face, said bore having a constriction therein providing a front and a rear shoulder; and a contact assembly including an elongated metallic contact having a forward body portion and a rearward conductor receiving portion, said body portion including a recess therein; a split tubular sleeve disposed contiguously and circumferentially about said contact; outwardly extending retaining means secured to said Contact assembly and rearward of and abutting said bore constriction rear shoulder; an outwardly struck up resilient portion from said sleeve forward of and abutting said bore constriction front shoulder, said struck up portion providing an exterior, outwardly and rearwardly extending carnming surface such that said struck up portion is disengaged -from said bore constriction front shoulder in response to -a longitudinal thrust from the direction of said housing front face on said camming surface, said struck up portion cooperating with said contact recess to prevent rearward movement of said contact relative to said sleeve, said contact recess providing space into which said struck up portion is disposed in response to said longitudinal thrust on said camrning surface; and means secured to said sleeve cooperating with said contact recess to prevent forward movement of said contact relative tto said sleeve; whereby said contact and sleeve may be concurrently inserted into, snap locked within and removed from said bore by way of said housing rear face. 7. An electrical connector assembly comprising: an insulation housing having a front and a rear face and a contact receiving bore therethrough from face to face, said bore having a constriction therein providing a front and a rear shoulder;

and a contact assembly including an elongated metallic contact having a forward body portion and a rearward conductor receiving portion, said body portion including a recess therein;

a split tubular sleeve disposed externally, contiguously and circumfcrentially about said contact;

outwardly extending retaining means integral with one of the elements of said contact assembly and rearward or and abutting said bore constriction rear shoulder;

an outwardly struck up resilient portion from said sleeve forward of and abutting said bore constriction front shoulder, said struck up portion providing an exterior, outwardly and rearwardly extending camming surface such that said struck up portion is disengaged from sa-id bore constriction front shoulder in response to a longitudinal thrust from the direction of said `housing front face on said camming surface, said struck up portion abutting within said contact recess to prevent rearward movement of said Contact relative to said sleeve, said contact recess providing space into which said struck up portion is disposed in response to said longitudinal thrust on said camming surface;

and a portion integral with said sleeve abutting within said contact recess to prevent forward movement of said Contact relative to said sleeve;

whereby said Contact and sleeve may be concurrently inserted into, snap locked within and removed from said bore `by way of said housing rear face.

References Cited in the lc of this patent UNITED STATES FATENTS 1,387,252 Fredricks Aug. 9, 1921 2,389,454 Picard Nov. 20, 1945 2,463,826 Thacker Mar. 8, 1949 2,477,849 Adams Aug. 2, 1949 2,689,337 Burtt et al. Sept. 14, 1954 2,715,215 Flora Aug. 9, 1955 2,716,744 Swanson et al Aug. 30, 1955 FOREIGN PATENTS 563,966 Belgium Jan. 3l, 1958 643,627 Great Britain Sept. 20, 1950 

